Thermionic tube



M. BAREISS THERMIONIC TUBE March 5, '1946.

Filed Feb. 21, 1942 5 Sheets-Sheet 1 ATTORNEYS March 5. 1946. M. BARElss 2,395,835

` THERMIONIC TUBE Filed Feb. `2, 1942 3 lSheets-Sheet 2 INVENTOR.

/Vx Enki/5s WFM l y@ www ATTORNEYS March 5, 1946. M. BARElss THERMIONIG TUBE A Filed Febg 2, 1942 5 Sheets-Shleet 3 INVENTOR Max BME/ss BY m, Mbnylwi ATTORNEY Patented Mar. 5, 1946 THERMION IC TUBE Mair Bareiss, Livingston, N.,J., assignerv to ,T-ungf- -SoleIaamp .-Works --I nc., Newark, N. J., a corporation oiiDelaware Application-February 2, 1942, Serial No. 4293461 f vfolims. (Cl. o-27.5)

The presentv invention relates to thermionic tubes and comprises an improved-grid construction for'radio or other'thermionic tubes employing a plurality of grids. l

This application is a continuation inpart of application Ser. No. 319,998, iiledFebruary 21, 1940.

'One object of 'the' invention is'a novel and-'im'- proved grid structure for radio tubesvwhereby the lateral wires'orv` elements may be accurately lined for eiiicient tube voperation irrespective of the number of grids employed.

A further object of the-invention isa noveland improved unitary multiple grid structure capable of being mounted as a unitwith the grid elements thereof pre-formed and-spacedwith respect to each other.

A further object'of'theinvention is anovel and improved multiple gridv structure` characterized by fusing ofrinsulating spacers about the grid elements to forma rrigid unitary structure.

A further object of lthe invention isthepro'- duction of a multiple grid thermionic; tubeby pre-forming a multiple grid-'unit' withV the elements of thegrid supportedjand'spaced from each other by means of `suitableinsulating `devices and then mountingthe grid unit in a thermionic tube in operative relation withlthe other elements ofthe tube.

Other objects 'ofi the invention .WiILhereinafter appear.

A` further objectisa grid'structure whichis characterizedv by its; simplicity in. construction and assembly.

The 'improved construction may vbe employed Vin tubes'` having uniform spacingbetween the variousfgridsand between' the lateral wires or elements' of each gridlor intubes wherethegrids are noneuniformly spaced or the vvertical"A distances between lateral wires oru elements of.' each Vgrid arevaried. For. anV understanding. of, thee. invention reference may, be hadQto vthe accor'npanying drawings in .which various embodimentsof the invention are.illustrated.V Y Y i .l

"Fig..1, isaperspectiveview, partlyt broken away of anelectrode assembly of aA three grid radio tube-provided with an improved grd'construction embodyingthe invention;

Fig. 2'is a side'view ofithezaslsemblyfofFig; 1; Fig. .3; isz-a `vertical sectional view. taken" along -theline 4"--41 of Fig. 2; Y

Fig. 5is a fragmentary view illustrating faimod'- ied construction of grida Y l v` 'i i Fig. 6 isa sideview` oflan assembly embodying another modification of the invention ;A Y

Fig. `7is a viewof the-assembly of TFig. Gitaken at right angles thereto; .y A

Fig. 8 is a horizontal sectional View taken along the line 8`Bof Fig. 6; 'y

Fig. 9 is a fragmentary plan view-illustratinga novel method ofcon'structing a plurality -fof grids; Fig. 10 is aside view ofa; grid'assembly-incoi`y` porating the construction `ofFiga 9; f Fig. 11 is a -sideview'oftheassembly-offFigll0 taken at right angles thereto; Y i Fig. 121is-avviewv of= a'g'rid illustrating another embodimentv ofthe-inventioml Y Y Fig. 12a `is adiagrammatic seetionalfview along the linelZa-lZafofjFig. 12'; l 1' Fig. 12bis a vievvfsiiriilar-4 to Fig. lza-butfshowing the individual elements offthegridfo'f Fig. 12 turned through ninety degrees;

Fig; 13 is a side5view `of a grid assembly incorl porating the construction'ofF-ig-IZ;

Fig. 14 is a perspective Viewillustratin'g the method of mounting gridsof the typeofthatof Fig. 12jto form an assemblyfdiiering fromthat of Fig. 13-;`and "Y v I Fig. 15 is a horizontal 'sectional View ofafgfrid assembly constructed by the method illustrated in'Fig.14.v

The radio tube electrodeassembly ofi Figsf 1 to 4 inclusive is shownfas including a conventional cathode 2'; and anodes' 4f carried between the usual spacing' discs tr of'rnica: orf-"otherfinfsulating material "and mounted on-apress '8; In

accordance with the invention; thefthreeffgrids I0, I2r andv I4 areveach composedjof twosets` of lateral WiresIUa, l2aandi Maand the wires of each set are 'electrically' connected by vertical rods or postsdb. I2bandv 1451). VThe setsgof grid` I0 -are electrically connected beneathfthe lower disc 6by a cross Wirel 10c connecting-the pasts 10b; Similarly,jposts |212 arev connected by cross wires I2'c and posts Hlbrare Vconnected by cross wire.' I 4c;-the cross`v wires liuc; l2cand 14o-forming convenient points-off connectionu for thelead-in wires of the tube'.` 'Thewires Illa', 12a andZ Illa are connected tothe-rods 10b, I2bj and Mb respectively in anyV suitable manner,Y as b y welding or swaging into cuts on the rods.

Mounted betweenthe discs-6 are two vertical'insulating sheetslB of 'glassorother ceramic inaterial` through which pass the endsoivv allthe lateral grid wires` and" to` which these wires4` are fused; As shown best in Fig. '2 each lateral Wire Illa is aligned with one of the wires I2a of each set of grid I2, with one of the wires I4a of each set of grid I4 and with one of the wires Ilia of the other set of grid I0. The fusing of the ends of the lateral wiresin the sheets I6 insures this parallel alignment of the various lateral wires and gives a sturdy and compact construction of the grid assembly. p

As shown in Fig. 4, the sheets or plates I6 are provided with rough'surfaces to decrease electrical leakage currents due to material deposited of the various grids I0, I2 and I4 are all aligned in horizontal planes as in the other modifications of the invention, but the vertical spacing between the horizontal planes varies, adjacent wires being closer together at the top and bottom than in the middle. This type of construction will also result in lower random tube noise. The lateral wires of the grids are shown mountedin the insulating sheets YI6 as Vwith ,the embodiment of Figs. 1 to 4, but the alternative construction of Figs. 6 and 7 could as well be employed with the from hot parts such as the cathode coating. As`

shown upstanding ribs Il are upset along the .inner surfaces to shield-the grooves I8 against Y deposit, and roughened surfaces'may also be provided on the other side.

In the embodiment of the invention illustrated in Figs. 1 to 4 inclusive each grid is constructed of a plurality of separate lateral wires. In Fig. 5 is illustrated a grid I8 in'which the lateral wires are made from a. single Wire which is threaded back and forth through the, sheet I6 with the horizontal reaches parallel and equidistant. One or more of the grids VIII, I2 vfor I4 could be constructedlike grid I8 of Fig. 5in which case the vertical rods Ib, I 2b and I4b could be omitted except for suitable provision for electrically connecting the sets of each gridktogether and to the lead-in wires. Y

The elements ofy the multiple grid unit thus formed are rmly and rigidly supported and spaced from each other in a permanent manner and the same may be readilymounted in the tube without dislocation or shifting of the elements with respect to each other. Moreover, the relation of the elements of the grid with respect to each other are retained permanently in` the position to give the accuracy in function and results desired. The insulating sheets I6, for example, being fused about the wires of the grids, retains them during the life; of the tube in the exact pre-determined relationship. `After the preforming of the multiple grid unit comprising the insulating vsheets I6, which are fused to the elements of the grids, the next step is the asand this may be eiected with greatl facility because it is only necessary toadjust the multiple gridunit and anode with respect to each other,

the multiple grid having previously been formed into a rigid precision structure.

In Figs. 6, '7 and 8 an alternative construction embodying the invention is illustrated.- In this arrangement, the spacing andsupporting sheets I6 for the lateral grid wires are omitted and con- Y spectively or swagedinto cuts therein as in the embodiment. ofthe invention illustrated inFgs.

1 tol 4. For simplicity the lead-in wire connections and other elements of the tube, except the cathode 2, have been omitted from these as well as from other figures of the drawings as forming no part of the present invention. Y, Y

If remote` cut-off characteristics are desired, the vertical spacingl between the lateral wires may ,be varied as indicated inthe modification of Figs. `1 0 andll. I n this arrangement the lateral wires spacing arrangement of Figs. 10 and 1l.

Y In the embodiments of the invention above set forth the lateral wires are shown as not only aligned with each other on either side of the 'cathodabut the wires on one side are aligned on one side of the cathode be aligned with each other.

In Fig. 9 is illustrated a convenient methodof constructing the grids IU, I2 andA I4 which insures the proper lateral alignment ofthe wires.L A single wire 24 is passed back and forth through the sheets IE with the lengths between the sheets kept parallel and spaced corresponding to the desired distance between the grids. The connecting portions 25 are then cut off so that the resulting individual lengths become the aligned lateral wires of the various grids. It will be understood, of course, that additional layers of the grids are then built up to provide the complete grid assembly and that connecting pieces have to be provided as described above.

- In addition to the other advantages the improved grid has the advantage that it is possible to devise equipment to assemble the whole grid sembling of this unit into the thermionic device ,K

structure without the use lof skilled labor.l

In Figs 12 and 12a is illustrated Va grid 23 formed. by stamping thin sheet metal so as to leave the .thin parallel strips 29 separated by openings 30 and held together by the uncut sides and 'ends 32 of the plate. 5 A plurality. of these grids 28 may be conveniently mounted in vertical spaced relation between mica or Aother insulating plates 34 as shown in Fig. 13 to form a grid Vassembly in which the individual elements 29 ofthe various' grids lie in parallel planes as do the horizontal grid wires of the embodiments of the invention illustrated in Figs. 1 to i1. If desired in order to decrease the grid area interposed to the electron stream from the cathode, the strips or elements 29, prior to mounting of the grids 28 may be twisted through ninety degrees as indicated in Fig. 12b., y

In Figs. 14 and 15 is illustrated Van alternative method of constructing a grid assembly from stamped. metal sheets. In this method the stamped sheets 36 are first. positioned in horizontal planes and held in spaced relationby any suitable jig. Supporting sheets I6 of insulating material, such as described in connection with Figs. 1 to 5`and 9 to 11 are then fused about the Aends of the strips'4IJ of the sheets 36. The material of which the sheets I6 are made, may be glass, ceramic material, or other fusible insulating material capable of being fused about the grid elements. The sides 42 of the plates 36 are then sheared oi to separate the strips or elements 40, as indicated by they dotted lines 43 in Fig. 14. Metal wires or rods 38 are then welded or otherwise secured to the ends of strips 40 protruding through the sheets I6. 'I'he resulting structure, mounted between insulating plates 34, such as shown in Fig. 13, is a grid assembly in which each grid is formed of one element 40 from each sheet 36 connected electrically by therods 38 and supported by the insulating sheets I6. Each element of each grid is thus necessarily iparallel with and in the same plane with an element of another grid, because having been formed from the same horizontal sheet.

The invention has now been described in connection with various embodiments thereof, obviously various changes might be made in the particular constructions illustrated without departing from the spirit of the invention as defined in the accompanying claims.

I claim:

1. A grid assembly for vacuum tubes comprising in combination a grid formed of a plurality of parallel lateral wires and a vertical conducting rod to which each of said wires is secured, a pair of spaced insulating sheets fused to said wires adjacent opposite ends thereof to support the same, and a second grid formed of a plurality of parallel lateral wires and a second conducting rod to which said last mentioned wires are secured, said last mentioned Wires being likewise fused to and supported by said insulating sheets, each lateral wire of said rst mentioned grid being disposed parallel to and in the same horizontal plane with a lateral wire of said second mentioned grid.

2. A grid assembly for vacuum tubes comprising in combination a grid formed of a plurality of parallel lateral wires and a vertical conducting rod to which each of said wires is secured, a pair of spaced insulating sheets fused to said wires adjacent opposite ends thereof to support the same, a second grid formed of a plurality of parallel lateral wires and a second conducting rod to which said last mentioned wires are secured, said last mentioned wires being likewise fused to and supported by said insulating sheets, each lateral wire of said rst mentioned grid being disposed parallel to and in the same horizontal Aplane with a lateral wire of said second mentioned grid, and a third grid likewise composed of a plurality of parallel lateral wires and a vertical conducting rod secured thereto, s aid wires of said third grid being likewise fused within and supported by said insulating sheets with each wire disposed parallel to and in the same plane with a wire of each of said rst mentioned grids.

3. A grid assembly for vacuum tubes comprising in combination a plurality of grids each comprising a plurality of parallel lateral wires electrically connected together and insulating sheets yof ceramic material fused about the ends of all of said lateral wires of all of said grids for supporting and spacing the same, the ends of said wires being electrically connected beyond one of said sheets.

4. A step in the method of forming a plurality of grids with aligned lateral wires which comprises weaving a wire back and forth in a horizontal plane through spaced vertical sheets of ceramic material While keeping parallel the lengths of the wire between the sheets, fusing the ceramic material to the wire and then cutting off the connecting portions of wire beyond the sheets.

5. In a thermionic tube, an improved multiple grid construction comprising in combination a plurality of lateral wires aligned in different vertical planes, means electrically connecting the wires of each plane to form a grid, and combined supporting and aligning means for the multiple grid construction serving to maintain each lateral wire of one grid in the same plane with a lateral wire of another' grid, said supporting and aligning means comprising sheets of insulating material fused about said lateral wires to support and hold the same in alignment.

6. A unitary grid structure for thermionic tubes comprising a plurality of parallel lateralv wires arranged in horizontal and vertical planes, vertically disposed sheets of ceramic material fused about the ends of said wires to support and align the same, means electrically connecting the wires of each vertical plane together to form a grid, and horizontal insulating spacing members engaging said ceramic sheets at opposite ends thereof.

7. A unitary multiple grid structure for use in thermionic tubes comprising a plurality of grids each composed of a plurality of electrically connected grid elements and insulators fused to said elements for supporting and spacing the same.

MAX BAREISS. 

